Teledyne 514 Instruction Manual page 45

Symptom
Output goes to zero or full
scale (either extreme).
Discrepancy between re-
corder trace (current) and
reading on concentration
meter.
Output drifts slowly up or
down.
Maintenance & Troubleshooting 5.0
Cause
E-to-I converter defective
(check output transistors Q3,
Q4 or Q5).
Failure of A1 IC (log amplifier) in
log amplifier circuit.
Failure of I-to-E converter.
Failure of extended voltage
amplifier.
E-to-I converter defective.
Defect in temperature controller
circuitry.
Teledyne Analytical Instruments
A Business Unit of Teledyne Electronic Technologies
Corrective Action
Check/replace, if required. If
meter sits on zero, also check
auto. gain control circuit card;
replace, if required.
Check log amplifier for 0 to 0.4
VDC full scale output. If IC A1 is
replaced, make sure that
balance potentiometers are
adjusted. Refer to Table VI.
Check input to pin 14. If input is
correct, check output at pin 15
for 0 to +4 VDC full scale.
Replace I-to-E converter, if
required.
Check input at pin 2 and output
at pin 5. If pin 5 output voltage
is not 0-1 VDC full scale output,
check/replace circuit card.
Check/replace, if required. Pay
particular attention to the output
transistors (Q3, Q4 and Q5).
Check/replace fuse F1, if
necessary.
Check/replace temperature
controller circuit card, as
required.
5–7